Utilisation and application of implementation science in complex suicide prevention interventions: A systematic review

Little is known about how complex, multilevel, and multicomponent suicide prevention interventions work in real life settings. Understanding the methods used to systematically adopt, deliver, and sustain these interventions could ensure that they have the best chance of unfolding their full effect. This systematic review aimed to examine the application and extent of utilisation of implementation science in understanding and evaluating complex suicide prevention interventions. The review adhered to updated PRISMA guidelines and was prospectively registered with PROSPERO (CRD42021247950). PubMed, CINAHL, PsycINFO, ProQuest, SCOPUS and CENTRAL were searched. All English-language records (1990–2022) with suicide and/or self-harm as the primary aims or targets of intervention were eligible. A forward citation search and a reference search further bolstered the search strategy. Interventions were considered complex if they consisted of three or more components and were implemented across two or more levels of socio-ecology or levels of prevention. One hundred thirty-nine records describing 19 complex interventions were identified. In 13 interventions, use of implementation science approaches, primarily process evaluations, was explicitly stated. However, extent of utilisation of implementation science approaches was found to be inconsistent and incomprehensive. The inclusion criteria, along with a narrow definition of complex interventions may have limited our findings. Understanding the implementation of complex interventions is crucial for unlocking key questions about theory-practice knowledge translation. Inconsistent reporting and inadequate understanding of implementation processes can lead to loss of critical, experiential knowledge related to what works to prevent suicide in real world settings.